Pneumatic trunnion mounted ball valve is a two-way valve with unlimited flow direction. The middle flange is connected by studs, and the upper and lower valve stems are equipped with sliding bearings to reduce friction, and the operation is labor-saving and stable. Under normal conditions: when the pressure is low, the valve seat seal relies on the spring preload to make the valve seat close to the ball to seal. When the pressure is high, the piston effect is formed on the valve seat. Under the pressure of the upstream medium, the valve seat presses the ball to seal. Pneumatic trunnion mounted ball valve, pneumatic ball valve, which is widely used in the process control system to realize on or off. Pneumatic fixed ball valve is a high-performance ball valve, which is suitable for long-distance pipelines and general industrial pipelines. Its strength, safety, and resistance to harsh environment have been specially considered in the design, and it is suitable for all kinds of corrosive and non corrosive media.